topic How to simplify multiline expression into 1 expression in Developers Questions

How to simplify multiline expression into 1 expression

Yeaton — Mon, 10 Feb 2025 22:28:51 GMT

Hello,

I've been trying to create a way to return the slope of a line by using the elevation values obtained via the intersection of the start and end vertex of the line with topo contours. Creating separate scripts for attribute fields of the line (i.e., start elv, end elv, length) and then using those values in an equation field worked, but it takes a very long time to process. I thought a viable alternative is to configure a popup with the same scripts condensed into one arcade expression. I tried to configure the pop up with multi line script but it only returns the start vertex elevation value.

Any advice is much appreciated.

The script is below:

//Start vertex (upper elevation) of line used for slope
var paths = Geometry($feature).paths
var line = paths[0][0]

//Selecting the elevation of the contour that is intersected by the start vertex
var x = featuresetbyname($datastore,"Homer_2ft_contour_Lidar_Gen")
for(var f in x){
if(intersects(line,f)){
return f.Contour}
}

//End vertex of line used for slope
Var p = paths[0][1]

//End vertex (lower elevation) of line used for slope
var y = featuresetbyname($datastore,"Homer_2ft_contour_Lidar_Gen")
for(var g in y){
if(intersects(p,g)){
return g.Contour}
}

//Equation to return slope of line
var z = (f-g)/$feature.Shape_Length * 100
return z

Best Regards,

A. Yeaton

Re: How to simplify multiline expression into 1 expression

KenBuja — Tue, 11 Feb 2025 16:35:53 GMT

It's giving you only the beginning vertex since you have a return function when you get an intersecting contour. You want to save that value and use it later. This shows two different outputs to select from, only the slope or the start elevation, the end elevation, and the slope. It also included breaks so you don't have to loop through all the contours.

//Start vertex (upper elevation) of line used for slope var paths = Geometry($feature).paths; var line = paths[0][0]; var begin = 0; var end = 0; //Selecting the elevation of the contour that is intersected by the start vertex var x = featuresetbyname($datastore, "Homer_2ft_contour_Lidar_Gen"); for (var f in x) { if (intersects(line, f)) { begin = f.Contour; break; } } //End vertex of line used for slope var p = paths[0][1]; //End vertex (lower elevation) of line used for slope var y = featuresetbyname($datastore, "Homer_2ft_contour_Lidar_Gen"); for (var g in y) { if (intersects(p, g)) { end = g.Contour; break; } } //Equation to return slope of line return (begin - end) / $feature.Shape_Length * 100; //or if you want all values, you can use this return return `Start elevation: ${begin} End elevation: ${end} Slope: ${(begin - end) / $feature.Shape_Length * 100}`;

Re: How to simplify multiline expression into 1 expression

Yeaton — Tue, 11 Feb 2025 18:18:02 GMT

Thanks for the prompt reply, Ken! I will give this a try and let you know how it goes.

Best,

Aaron

Re: How to simplify multiline expression into 1 expression

Yeaton — Wed, 12 Feb 2025 23:17:17 GMT

Thanks Ken, your script worked nicely.

Best,

Aaron